Description
Armstrong S-55-1 AB All Bronze 1/2HP Pump | Ultimate Product Guide
The Armstrong S-55-1 AB, part number 106284MF-133, is a versatile and durable in-line centrifugal circulator renowned for its reliability in critical applications. As part of the legendary Armstrong Series S & H line, this all-bronze constructed pump is specifically engineered for use in potable (domestic) water systems, making it a safe and corrosion-resistant choice for homeowners and HVAC professionals alike.
Powered by a dependable 1/2 HP motor, this pump is designed to handle a wide range of duties, from circulating hot and chilled water in hydronic heating and cooling systems to boosting pressure in domestic water lines and managing multi-zone setups. Its trusted design, proven over decades of service in the field, offers a perfect blend of performance, longevity, and material safety.
Detailed Technical Specifications
| Feature | Specification |
|---|---|
| Manufacturer | Armstrong Pumps |
| Series | Series S & H |
| Part Number | 106284MF-133 |
| Model | S-55-1 AB |
| Pump Type | In-Line Centrifugal Circulator |
| Horsepower (HP) | 1/2 HP |
| Construction | All Bronze |
| Connection Type | Flanged (Standard S-55) |
| Motor Type | Standard PSC (Permanent Split Capacitor) |
| Voltage | 115V / 120V (Standard Residential) |
| Phase | Single Phase |
| Service | Potable Water, Hydronic Heating/Cooling, Industrial |
*Note: For precise performance specs (GPM, Head), always consult the official Armstrong Series S performance curve for the S-55-1 AB model.*
Key Features & Benefits
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All-Bronze Construction: Provides excellent corrosion resistance and is safe for potable water systems.
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Proven Reliability: A time-tested design trusted by HVAC professionals for decades.
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Versatile Applications: Suitable for closed-loop hydronics and open-loop domestic water.
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Flanged Connections: Ensure a strong, leak-free seal and are standard for this pump size.
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Mechanical Seal: Designed for long life and minimal maintenance.
Armstrong S-55-1 AB vs. Other Pump Types: Comparison Table
This table highlights the ideal use cases for this specific pump.
| Feature | Armstrong S-55-1 AB (All Bronze) | Cast Iron Circulator (e.g., Taco 1900) | High-Efficiency ECM Circulator |
|---|---|---|---|
| Primary Use | Potable Water, Hydronics | Closed-Loop Hydronics Only | Closed-Loop Hydronics, DHW |
| Construction | All Bronze (Potable Safe) | Cast Iron (Not Potable Safe) | Bronze/Composite (Often Potable Safe) |
| Efficiency | Standard Efficiency | Standard Efficiency | Very High Efficiency |
| Durability | Excellent, Corrosion-Resistant | Excellent (in closed loops) | Excellent |
| Initial Cost | Moderate | Moderate | High |
| Best For | Domestic Water Boosting, Well Tanks | Commercial Boiler Systems | Energy-Conscious Hydronic Systems |
Frequently Asked Questions (FAQ)
Q1: Is this pump safe for drinking water?
A: Yes, absolutely. The key feature of the “AB” (All Bronze) model is its construction from corrosion-resistant bronze, which is fully safe and approved for use in potable (drinking) water systems. This distinguishes it from cast iron pumps, which are not.
Q2: What is the difference between “bronze-fitted” and “all bronze”?
A: “Bronze-fitted” typically means the pump has a cast iron body with key wear components (like the impeller) made of bronze. “All Bronze” means the entire pump wet-end (casing, impeller, etc.) is constructed from bronze, making it suitable for potable water.
Q3: What are typical applications for this pump?
A: This pump is incredibly versatile. Common uses include:
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Domestic Water Pressure Boosting
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Hot Water Recirculation Loops
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Hydronic (Boiler-Based) Heating Systems
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Chilled Water Cooling Systems
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Supply from Storage Tanks
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Industrial Water Transfer
Q4: Does it come with a built-in flow control or check valve?
A: No, the Armstrong Series S circulators are standard pumps. Flow control valves, check valves, and isolation flanges are typically purchased as separate accessories to create a complete pump package.
Q5: Is the motor serviceable?
A: Yes, these pumps are designed for serviceability. The motor is a separate component that can be replaced if it fails. The mechanical seal can also be replaced to address leaks.
Q6: What is the warranty?
A: Armstrong typically offers a 1-year warranty on their circulators. Always confirm the specific warranty terms with your supplier or Armstrong’s official policy.
Pros and Cons
Pros:
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Potable Water Safe: The all-bronze construction is its biggest advantage, allowing for safe use in domestic water applications.
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Proven Durability: A simple, robust, and time-tested design that HVAC professionals know and trust.
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Corrosion Resistance: Excellent resistance to corrosion in both open and closed-loop systems.
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Versatility: Can be used across a wide range of applications, from heating to domestic water.
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Flanged Connections: Provide a more robust and reliable connection than threaded unions on larger pumps.
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Brand Reputation: Armstrong is a respected and established name in commercial and residential pumping.
Cons:
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Standard Efficiency: Lacks the advanced ECM motor technology of newer pumps, resulting in higher energy consumption over time.
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Manual Operation: Does not have built-in variable speed or smart controls; it runs at a fixed speed when powered on.
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Weight: The all-bronze construction makes it heavier than equivalent composite-bodied pumps.
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Noise Level: Will be louder than modern, high-efficiency, variable-speed circulators.
Conclusion & Best Applications
The Armstrong S-55-1 AB (106284MF-133) is a classic, no-nonsense workhorse built for reliability and safety. It is the ideal choice for applications where material compatibility and proven performance are more critical than having the latest energy-saving technology.
You should choose this pump if:
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You need a pump for domestic drinking water pressure boosting or recirculation.
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You are replacing an old circulator in a potable water or hydronic system and require a durable, direct replacement.
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You value a simple, reliable, and serviceable design from a trusted manufacturer.
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The application requires the corrosion resistance of all-bronze construction.
For contractors and homeowners who need a dependable pump for safe water handling, the Armstrong Series S All Bronze circulator remains a top-tier, trusted choice.
Disclaimer: Installation must comply with all local plumbing and electrical codes. For potable water applications, all installed components must be certified for drinking water use. Professional installation is recommended.








